Dr. Marcia Grant will serve as Core Director of the Biostatistics Core in collaboration with our Statistician from Vital Research, Dr. Gwen Uman. Dr's Grant and Uman have collaborated in research projects since 1999. The Biostatistics Core (BC) of this Program Project Grant (PPG) provides statistical and data management support for each of the PPG projects and the other cores. The investigators in the BC have demonstrable statistical experience spanning diverse fields such as basic science research, translational and immunologic studies, clinical trials, observational cohort studies, survey designs and psychometric studies. This comprehensive, centralized BC assures that each PPG investigator receives independent and appropriate statistical support in the collaborative development of study designs and protocol development, state of the art data analysis, data management resources, and abstract and manuscript preparation. The BC investigators will routinely meet with investigators and key staff from project inception to completion in order to provide scientific advice on study design, statistical design, instrument design and development, data collection, and data management issues emerging in the projects.